drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  27  *
  28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  29  */
  30
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/proc_fs.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/acpi.h>
  38 #include <linux/dmi.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/sched.h>        /* need_resched() */
  41 #include <linux/pm_qos_params.h>
  42 #include <linux/clockchips.h>
  43 #include <linux/cpuidle.h>
  44 #include <linux/irqflags.h>
  45
  46 /*
  47  * Include the apic definitions for x86 to have the APIC timer related defines
  48  * available also for UP (on SMP it gets magically included via linux/smp.h).
  49  * asm/acpi.h is not an option, as it would require more include magic. Also
  50  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  51  */
  52 #ifdef CONFIG_X86
  53 #include <asm/apic.h>
  54 #endif
  55
  56 #include <asm/io.h>
  57 #include <asm/uaccess.h>
  58
  59 #include <acpi/acpi_bus.h>
  60 #include <acpi/processor.h>
  61 #include <asm/processor.h>
  62
  63 #define PREFIX "ACPI: "
  64
  65 #define ACPI_PROCESSOR_CLASS            "processor"
  66 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  67 ACPI_MODULE_NAME("processor_idle");
  68 #define ACPI_PROCESSOR_FILE_POWER       "power"
  69 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  70 #define C2_OVERHEAD                     1       /* 1us */
  71 #define C3_OVERHEAD                     1       /* 1us */
  72 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  73
  74 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  75 module_param(max_cstate, uint, 0000);
  76 static unsigned int nocst __read_mostly;
  77 module_param(nocst, uint, 0000);
  78
  79 static unsigned int latency_factor __read_mostly = 2;
  80 module_param(latency_factor, uint, 0644);
  81
  82 static s64 us_to_pm_timer_ticks(s64 t)
  83 {
  84         return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
  85 }
  86 /*
  87  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  88  * For now disable this. Probably a bug somewhere else.
  89  *
  90  * To skip this limit, boot/load with a large max_cstate limit.
  91  */
  92 static int set_max_cstate(const struct dmi_system_id *id)
  93 {
  94         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  95                 return 0;
  96
  97         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
  98                " Override with \"processor.max_cstate=%d\"\n", id->ident,
  99                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 100
 101         max_cstate = (long)id->driver_data;
 102
 103         return 0;
 104 }
 105
 106 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 107    callers to only run once -AK */
 108 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 109         { set_max_cstate, "Clevo 5600D", {
 110           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 111           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 112          (void *)2},
 113         {},
 114 };
 115
 116
 117 /*
 118  * Callers should disable interrupts before the call and enable
 119  * interrupts after return.
 120  */
 121 static void acpi_safe_halt(void)
 122 {
 123         current_thread_info()->status &= ~TS_POLLING;
 124         /*
 125          * TS_POLLING-cleared state must be visible before we
 126          * test NEED_RESCHED:
 127          */
 128         smp_mb();
 129         if (!need_resched()) {
 130                 safe_halt();
 131                 local_irq_disable();
 132         }
 133         current_thread_info()->status |= TS_POLLING;
 134 }
 135
 136 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 137
 138 /*
 139  * Some BIOS implementations switch to C3 in the published C2 state.
 140  * This seems to be a common problem on AMD boxen, but other vendors
 141  * are affected too. We pick the most conservative approach: we assume
 142  * that the local APIC stops in both C2 and C3.
 143  */
 144 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 145                                    struct acpi_processor_cx *cx)
 146 {
 147         struct acpi_processor_power *pwr = &pr->power;
 148         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 149
 150         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 151                 return;
 152
 153         if (boot_cpu_has(X86_FEATURE_AMDC1E))
 154                 type = ACPI_STATE_C1;
 155
 156         /*
 157          * Check, if one of the previous states already marked the lapic
 158          * unstable
 159          */
 160         if (pwr->timer_broadcast_on_state < state)
 161                 return;
 162
 163         if (cx->type >= type)
 164                 pr->power.timer_broadcast_on_state = state;
 165 }
 166
 167 static void lapic_timer_propagate_broadcast(void *arg)
 168 {
 169         struct acpi_processor *pr = (struct acpi_processor *) arg;
 170         unsigned long reason;
 171
 172         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 173                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 174
 175         clockevents_notify(reason, &pr->id);
 176 }
 177
 178 /* Power(C) State timer broadcast control */
 179 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 180                                        struct acpi_processor_cx *cx,
 181                                        int broadcast)
 182 {
 183         int state = cx - pr->power.states;
 184
 185         if (state >= pr->power.timer_broadcast_on_state) {
 186                 unsigned long reason;
 187
 188                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 189                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 190                 clockevents_notify(reason, &pr->id);
 191         }
 192 }
 193
 194 #else
 195
 196 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 197                                    struct acpi_processor_cx *cstate) { }
 198 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 199 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 200                                        struct acpi_processor_cx *cx,
 201                                        int broadcast)
 202 {
 203 }
 204
 205 #endif
 206
 207 /*
 208  * Suspend / resume control
 209  */
 210 static int acpi_idle_suspend;
 211 static u32 saved_bm_rld;
 212
 213 static void acpi_idle_bm_rld_save(void)
 214 {
 215         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 216 }
 217 static void acpi_idle_bm_rld_restore(void)
 218 {
 219         u32 resumed_bm_rld;
 220
 221         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 222
 223         if (resumed_bm_rld != saved_bm_rld)
 224                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 225 }
 226
 227 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 228 {
 229         if (acpi_idle_suspend == 1)
 230                 return 0;
 231
 232         acpi_idle_bm_rld_save();
 233         acpi_idle_suspend = 1;
 234         return 0;
 235 }
 236
 237 int acpi_processor_resume(struct acpi_device * device)
 238 {
 239         if (acpi_idle_suspend == 0)
 240                 return 0;
 241
 242         acpi_idle_bm_rld_restore();
 243         acpi_idle_suspend = 0;
 244         return 0;
 245 }
 246
 247 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
 248 static void tsc_check_state(int state)
 249 {
 250         switch (boot_cpu_data.x86_vendor) {
 251         case X86_VENDOR_AMD:
 252         case X86_VENDOR_INTEL:
 253                 /*
 254                  * AMD Fam10h TSC will tick in all
 255                  * C/P/S0/S1 states when this bit is set.
 256                  */
 257                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 258                         return;
 259
 260                 /*FALL THROUGH*/
 261         default:
 262                 /* TSC could halt in idle, so notify users */
 263                 if (state > ACPI_STATE_C1)
 264                         mark_tsc_unstable("TSC halts in idle");
 265         }
 266 }
 267 #else
 268 static void tsc_check_state(int state) { return; }
 269 #endif
 270
 271 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 272 {
 273
 274         if (!pr)
 275                 return -EINVAL;
 276
 277         if (!pr->pblk)
 278                 return -ENODEV;
 279
 280         /* if info is obtained from pblk/fadt, type equals state */
 281         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 282         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 283
 284 #ifndef CONFIG_HOTPLUG_CPU
 285         /*
 286          * Check for P_LVL2_UP flag before entering C2 and above on
 287          * an SMP system.
 288          */
 289         if ((num_online_cpus() > 1) &&
 290             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 291                 return -ENODEV;
 292 #endif
 293
 294         /* determine C2 and C3 address from pblk */
 295         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 296         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 297
 298         /* determine latencies from FADT */
 299         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 300         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 301
 302         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 303                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 304                           pr->power.states[ACPI_STATE_C2].address,
 305                           pr->power.states[ACPI_STATE_C3].address));
 306
 307         return 0;
 308 }
 309
 310 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 311 {
 312         if (!pr->power.states[ACPI_STATE_C1].valid) {
 313                 /* set the first C-State to C1 */
 314                 /* all processors need to support C1 */
 315                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 316                 pr->power.states[ACPI_STATE_C1].valid = 1;
 317                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 318         }
 319         /* the C0 state only exists as a filler in our array */
 320         pr->power.states[ACPI_STATE_C0].valid = 1;
 321         return 0;
 322 }
 323
 324 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 325 {
 326         acpi_status status = 0;
 327         acpi_integer count;
 328         int current_count;
 329         int i;
 330         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 331         union acpi_object *cst;
 332
 333
 334         if (nocst)
 335                 return -ENODEV;
 336
 337         current_count = 0;
 338
 339         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 340         if (ACPI_FAILURE(status)) {
 341                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 342                 return -ENODEV;
 343         }
 344
 345         cst = buffer.pointer;
 346
 347         /* There must be at least 2 elements */
 348         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 349                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 350                 status = -EFAULT;
 351                 goto end;
 352         }
 353
 354         count = cst->package.elements[0].integer.value;
 355
 356         /* Validate number of power states. */
 357         if (count < 1 || count != cst->package.count - 1) {
 358                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 359                 status = -EFAULT;
 360                 goto end;
 361         }
 362
 363         /* Tell driver that at least _CST is supported. */
 364         pr->flags.has_cst = 1;
 365
 366         for (i = 1; i <= count; i++) {
 367                 union acpi_object *element;
 368                 union acpi_object *obj;
 369                 struct acpi_power_register *reg;
 370                 struct acpi_processor_cx cx;
 371
 372                 memset(&cx, 0, sizeof(cx));
 373
 374                 element = &(cst->package.elements[i]);
 375                 if (element->type != ACPI_TYPE_PACKAGE)
 376                         continue;
 377
 378                 if (element->package.count != 4)
 379                         continue;
 380
 381                 obj = &(element->package.elements[0]);
 382
 383                 if (obj->type != ACPI_TYPE_BUFFER)
 384                         continue;
 385
 386                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 387
 388                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 389                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 390                         continue;
 391
 392                 /* There should be an easy way to extract an integer... */
 393                 obj = &(element->package.elements[1]);
 394                 if (obj->type != ACPI_TYPE_INTEGER)
 395                         continue;
 396
 397                 cx.type = obj->integer.value;
 398                 /*
 399                  * Some buggy BIOSes won't list C1 in _CST -
 400                  * Let acpi_processor_get_power_info_default() handle them later
 401                  */
 402                 if (i == 1 && cx.type != ACPI_STATE_C1)
 403                         current_count++;
 404
 405                 cx.address = reg->address;
 406                 cx.index = current_count + 1;
 407
 408                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 409                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 410                         if (acpi_processor_ffh_cstate_probe
 411                                         (pr->id, &cx, reg) == 0) {
 412                                 cx.entry_method = ACPI_CSTATE_FFH;
 413                         } else if (cx.type == ACPI_STATE_C1) {
 414                                 /*
 415                                  * C1 is a special case where FIXED_HARDWARE
 416                                  * can be handled in non-MWAIT way as well.
 417                                  * In that case, save this _CST entry info.
 418                                  * Otherwise, ignore this info and continue.
 419                                  */
 420                                 cx.entry_method = ACPI_CSTATE_HALT;
 421                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 422                         } else {
 423                                 continue;
 424                         }
 425                         if (cx.type == ACPI_STATE_C1 &&
 426                                         (idle_halt || idle_nomwait)) {
 427                                 /*
 428                                  * In most cases the C1 space_id obtained from
 429                                  * _CST object is FIXED_HARDWARE access mode.
 430                                  * But when the option of idle=halt is added,
 431                                  * the entry_method type should be changed from
 432                                  * CSTATE_FFH to CSTATE_HALT.
 433                                  * When the option of idle=nomwait is added,
 434                                  * the C1 entry_method type should be
 435                                  * CSTATE_HALT.
 436                                  */
 437                                 cx.entry_method = ACPI_CSTATE_HALT;
 438                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 439                         }
 440                 } else {
 441                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 442                                  cx.address);
 443                 }
 444
 445                 if (cx.type == ACPI_STATE_C1) {
 446                         cx.valid = 1;
 447                 }
 448
 449                 obj = &(element->package.elements[2]);
 450                 if (obj->type != ACPI_TYPE_INTEGER)
 451                         continue;
 452
 453                 cx.latency = obj->integer.value;
 454
 455                 obj = &(element->package.elements[3]);
 456                 if (obj->type != ACPI_TYPE_INTEGER)
 457                         continue;
 458
 459                 cx.power = obj->integer.value;
 460
 461                 current_count++;
 462                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 463
 464                 /*
 465                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 466                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 467                  */
 468                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 469                         printk(KERN_WARNING
 470                                "Limiting number of power states to max (%d)\n",
 471                                ACPI_PROCESSOR_MAX_POWER);
 472                         printk(KERN_WARNING
 473                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 474                         break;
 475                 }
 476         }
 477
 478         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 479                           current_count));
 480
 481         /* Validate number of power states discovered */
 482         if (current_count < 2)
 483                 status = -EFAULT;
 484
 485       end:
 486         kfree(buffer.pointer);
 487
 488         return status;
 489 }
 490
 491 static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
 492 {
 493
 494         if (!cx->address)
 495                 return;
 496
 497         /*
 498          * C2 latency must be less than or equal to 100
 499          * microseconds.
 500          */
 501         else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 502                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 503                                   "latency too large [%d]\n", cx->latency));
 504                 return;
 505         }
 506
 507         /*
 508          * Otherwise we've met all of our C2 requirements.
 509          * Normalize the C2 latency to expidite policy
 510          */
 511         cx->valid = 1;
 512
 513         cx->latency_ticks = cx->latency;
 514
 515         return;
 516 }
 517
 518 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 519                                            struct acpi_processor_cx *cx)
 520 {
 521         static int bm_check_flag = -1;
 522         static int bm_control_flag = -1;
 523
 524
 525         if (!cx->address)
 526                 return;
 527
 528         /*
 529          * C3 latency must be less than or equal to 1000
 530          * microseconds.
 531          */
 532         else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 533                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 534                                   "latency too large [%d]\n", cx->latency));
 535                 return;
 536         }
 537
 538         /*
 539          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 540          * DMA transfers are used by any ISA device to avoid livelock.
 541          * Note that we could disable Type-F DMA (as recommended by
 542          * the erratum), but this is known to disrupt certain ISA
 543          * devices thus we take the conservative approach.
 544          */
 545         else if (errata.piix4.fdma) {
 546                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 547                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 548                 return;
 549         }
 550
 551         /* All the logic here assumes flags.bm_check is same across all CPUs */
 552         if (bm_check_flag == -1) {
 553                 /* Determine whether bm_check is needed based on CPU  */
 554                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 555                 bm_check_flag = pr->flags.bm_check;
 556                 bm_control_flag = pr->flags.bm_control;
 557         } else {
 558                 pr->flags.bm_check = bm_check_flag;
 559                 pr->flags.bm_control = bm_control_flag;
 560         }
 561
 562         if (pr->flags.bm_check) {
 563                 if (!pr->flags.bm_control) {
 564                         if (pr->flags.has_cst != 1) {
 565                                 /* bus mastering control is necessary */
 566                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 567                                         "C3 support requires BM control\n"));
 568                                 return;
 569                         } else {
 570                                 /* Here we enter C3 without bus mastering */
 571                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 572                                         "C3 support without BM control\n"));
 573                         }
 574                 }
 575         } else {
 576                 /*
 577                  * WBINVD should be set in fadt, for C3 state to be
 578                  * supported on when bm_check is not required.
 579                  */
 580                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 581                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 582                                           "Cache invalidation should work properly"
 583                                           " for C3 to be enabled on SMP systems\n"));
 584                         return;
 585                 }
 586         }
 587
 588         /*
 589          * Otherwise we've met all of our C3 requirements.
 590          * Normalize the C3 latency to expidite policy.  Enable
 591          * checking of bus mastering status (bm_check) so we can
 592          * use this in our C3 policy
 593          */
 594         cx->valid = 1;
 595
 596         cx->latency_ticks = cx->latency;
 597         /*
 598          * On older chipsets, BM_RLD needs to be set
 599          * in order for Bus Master activity to wake the
 600          * system from C3.  Newer chipsets handle DMA
 601          * during C3 automatically and BM_RLD is a NOP.
 602          * In either case, the proper way to
 603          * handle BM_RLD is to set it and leave it set.
 604          */
 605         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 606
 607         return;
 608 }
 609
 610 static int acpi_processor_power_verify(struct acpi_processor *pr)
 611 {
 612         unsigned int i;
 613         unsigned int working = 0;
 614
 615         pr->power.timer_broadcast_on_state = INT_MAX;
 616
 617         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 618                 struct acpi_processor_cx *cx = &pr->power.states[i];
 619
 620                 switch (cx->type) {
 621                 case ACPI_STATE_C1:
 622                         cx->valid = 1;
 623                         break;
 624
 625                 case ACPI_STATE_C2:
 626                         acpi_processor_power_verify_c2(cx);
 627                         break;
 628
 629                 case ACPI_STATE_C3:
 630                         acpi_processor_power_verify_c3(pr, cx);
 631                         break;
 632                 }
 633                 if (!cx->valid)
 634                         continue;
 635
 636                 lapic_timer_check_state(i, pr, cx);
 637                 tsc_check_state(cx->type);
 638                 working++;
 639         }
 640
 641         smp_call_function_single(pr->id, lapic_timer_propagate_broadcast,
 642                                  pr, 1);
 643
 644         return (working);
 645 }
 646
 647 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 648 {
 649         unsigned int i;
 650         int result;
 651
 652
 653         /* NOTE: the idle thread may not be running while calling
 654          * this function */
 655
 656         /* Zero initialize all the C-states info. */
 657         memset(pr->power.states, 0, sizeof(pr->power.states));
 658
 659         result = acpi_processor_get_power_info_cst(pr);
 660         if (result == -ENODEV)
 661                 result = acpi_processor_get_power_info_fadt(pr);
 662
 663         if (result)
 664                 return result;
 665
 666         acpi_processor_get_power_info_default(pr);
 667
 668         pr->power.count = acpi_processor_power_verify(pr);
 669
 670         /*
 671          * if one state of type C2 or C3 is available, mark this
 672          * CPU as being "idle manageable"
 673          */
 674         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 675                 if (pr->power.states[i].valid) {
 676                         pr->power.count = i;
 677                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 678                                 pr->flags.power = 1;
 679                 }
 680         }
 681
 682         return 0;
 683 }
 684
 685 #ifdef CONFIG_ACPI_PROCFS
 686 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 687 {
 688         struct acpi_processor *pr = seq->private;
 689         unsigned int i;
 690
 691
 692         if (!pr)
 693                 goto end;
 694
 695         seq_printf(seq, "active state:            C%zd\n"
 696                    "max_cstate:              C%d\n"
 697                    "maximum allowed latency: %d usec\n",
 698                    pr->power.state ? pr->power.state - pr->power.states : 0,
 699                    max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
 700
 701         seq_puts(seq, "states:\n");
 702
 703         for (i = 1; i <= pr->power.count; i++) {
 704                 seq_printf(seq, "   %cC%d:                  ",
 705                            (&pr->power.states[i] ==
 706                             pr->power.state ? '*' : ' '), i);
 707
 708                 if (!pr->power.states[i].valid) {
 709                         seq_puts(seq, "<not supported>\n");
 710                         continue;
 711                 }
 712
 713                 switch (pr->power.states[i].type) {
 714                 case ACPI_STATE_C1:
 715                         seq_printf(seq, "type[C1] ");
 716                         break;
 717                 case ACPI_STATE_C2:
 718                         seq_printf(seq, "type[C2] ");
 719                         break;
 720                 case ACPI_STATE_C3:
 721                         seq_printf(seq, "type[C3] ");
 722                         break;
 723                 default:
 724                         seq_printf(seq, "type[--] ");
 725                         break;
 726                 }
 727
 728                 if (pr->power.states[i].promotion.state)
 729                         seq_printf(seq, "promotion[C%zd] ",
 730                                    (pr->power.states[i].promotion.state -
 731                                     pr->power.states));
 732                 else
 733                         seq_puts(seq, "promotion[--] ");
 734
 735                 if (pr->power.states[i].demotion.state)
 736                         seq_printf(seq, "demotion[C%zd] ",
 737                                    (pr->power.states[i].demotion.state -
 738                                     pr->power.states));
 739                 else
 740                         seq_puts(seq, "demotion[--] ");
 741
 742                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
 743                            pr->power.states[i].latency,
 744                            pr->power.states[i].usage,
 745                            (unsigned long long)pr->power.states[i].time);
 746         }
 747
 748       end:
 749         return 0;
 750 }
 751
 752 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
 753 {
 754         return single_open(file, acpi_processor_power_seq_show,
 755                            PDE(inode)->data);
 756 }
 757
 758 static const struct file_operations acpi_processor_power_fops = {
 759         .owner = THIS_MODULE,
 760         .open = acpi_processor_power_open_fs,
 761         .read = seq_read,
 762         .llseek = seq_lseek,
 763         .release = single_release,
 764 };
 765 #endif
 766
 767 /**
 768  * acpi_idle_bm_check - checks if bus master activity was detected
 769  */
 770 static int acpi_idle_bm_check(void)
 771 {
 772         u32 bm_status = 0;
 773
 774         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 775         if (bm_status)
 776                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 777         /*
 778          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 779          * the true state of bus mastering activity; forcing us to
 780          * manually check the BMIDEA bit of each IDE channel.
 781          */
 782         else if (errata.piix4.bmisx) {
 783                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 784                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 785                         bm_status = 1;
 786         }
 787         return bm_status;
 788 }
 789
 790 /**
 791  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 792  * @cx: cstate data
 793  *
 794  * Caller disables interrupt before call and enables interrupt after return.
 795  */
 796 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 797 {
 798         /* Don't trace irqs off for idle */
 799         stop_critical_timings();
 800         if (cx->entry_method == ACPI_CSTATE_FFH) {
 801                 /* Call into architectural FFH based C-state */
 802                 acpi_processor_ffh_cstate_enter(cx);
 803         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 804                 acpi_safe_halt();
 805         } else {
 806                 int unused;
 807                 /* IO port based C-state */
 808                 inb(cx->address);
 809                 /* Dummy wait op - must do something useless after P_LVL2 read
 810                    because chipsets cannot guarantee that STPCLK# signal
 811                    gets asserted in time to freeze execution properly. */
 812                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 813         }
 814         start_critical_timings();
 815 }
 816
 817 /**
 818  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 819  * @dev: the target CPU
 820  * @state: the state data
 821  *
 822  * This is equivalent to the HALT instruction.
 823  */
 824 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 825                               struct cpuidle_state *state)
 826 {
 827         ktime_t  kt1, kt2;
 828         s64 idle_time;
 829         struct acpi_processor *pr;
 830         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 831
 832         pr = __get_cpu_var(processors);
 833
 834         if (unlikely(!pr))
 835                 return 0;
 836
 837         local_irq_disable();
 838
 839         /* Do not access any ACPI IO ports in suspend path */
 840         if (acpi_idle_suspend) {
 841                 local_irq_enable();
 842                 cpu_relax();
 843                 return 0;
 844         }
 845
 846         lapic_timer_state_broadcast(pr, cx, 1);
 847         kt1 = ktime_get_real();
 848         acpi_idle_do_entry(cx);
 849         kt2 = ktime_get_real();
 850         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 851
 852         local_irq_enable();
 853         cx->usage++;
 854         lapic_timer_state_broadcast(pr, cx, 0);
 855
 856         return idle_time;
 857 }
 858
 859 /**
 860  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 861  * @dev: the target CPU
 862  * @state: the state data
 863  */
 864 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 865                                   struct cpuidle_state *state)
 866 {
 867         struct acpi_processor *pr;
 868         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 869         ktime_t  kt1, kt2;
 870         s64 idle_time;
 871         s64 sleep_ticks = 0;
 872
 873         pr = __get_cpu_var(processors);
 874
 875         if (unlikely(!pr))
 876                 return 0;
 877
 878         if (acpi_idle_suspend)
 879                 return(acpi_idle_enter_c1(dev, state));
 880
 881         local_irq_disable();
 882         current_thread_info()->status &= ~TS_POLLING;
 883         /*
 884          * TS_POLLING-cleared state must be visible before we test
 885          * NEED_RESCHED:
 886          */
 887         smp_mb();
 888
 889         if (unlikely(need_resched())) {
 890                 current_thread_info()->status |= TS_POLLING;
 891                 local_irq_enable();
 892                 return 0;
 893         }
 894
 895         /*
 896          * Must be done before busmaster disable as we might need to
 897          * access HPET !
 898          */
 899         lapic_timer_state_broadcast(pr, cx, 1);
 900
 901         if (cx->type == ACPI_STATE_C3)
 902                 ACPI_FLUSH_CPU_CACHE();
 903
 904         kt1 = ktime_get_real();
 905         /* Tell the scheduler that we are going deep-idle: */
 906         sched_clock_idle_sleep_event();
 907         acpi_idle_do_entry(cx);
 908         kt2 = ktime_get_real();
 909         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 910
 911         sleep_ticks = us_to_pm_timer_ticks(idle_time);
 912
 913         /* Tell the scheduler how much we idled: */
 914         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 915
 916         local_irq_enable();
 917         current_thread_info()->status |= TS_POLLING;
 918
 919         cx->usage++;
 920
 921         lapic_timer_state_broadcast(pr, cx, 0);
 922         cx->time += sleep_ticks;
 923         return idle_time;
 924 }
 925
 926 static int c3_cpu_count;
 927 static DEFINE_SPINLOCK(c3_lock);
 928
 929 /**
 930  * acpi_idle_enter_bm - enters C3 with proper BM handling
 931  * @dev: the target CPU
 932  * @state: the state data
 933  *
 934  * If BM is detected, the deepest non-C3 idle state is entered instead.
 935  */
 936 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 937                               struct cpuidle_state *state)
 938 {
 939         struct acpi_processor *pr;
 940         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 941         ktime_t  kt1, kt2;
 942         s64 idle_time;
 943         s64 sleep_ticks = 0;
 944
 945
 946         pr = __get_cpu_var(processors);
 947
 948         if (unlikely(!pr))
 949                 return 0;
 950
 951         if (acpi_idle_suspend)
 952                 return(acpi_idle_enter_c1(dev, state));
 953
 954         if (acpi_idle_bm_check()) {
 955                 if (dev->safe_state) {
 956                         dev->last_state = dev->safe_state;
 957                         return dev->safe_state->enter(dev, dev->safe_state);
 958                 } else {
 959                         local_irq_disable();
 960                         acpi_safe_halt();
 961                         local_irq_enable();
 962                         return 0;
 963                 }
 964         }
 965
 966         local_irq_disable();
 967         current_thread_info()->status &= ~TS_POLLING;
 968         /*
 969          * TS_POLLING-cleared state must be visible before we test
 970          * NEED_RESCHED:
 971          */
 972         smp_mb();
 973
 974         if (unlikely(need_resched())) {
 975                 current_thread_info()->status |= TS_POLLING;
 976                 local_irq_enable();
 977                 return 0;
 978         }
 979
 980         acpi_unlazy_tlb(smp_processor_id());
 981
 982         /* Tell the scheduler that we are going deep-idle: */
 983         sched_clock_idle_sleep_event();
 984         /*
 985          * Must be done before busmaster disable as we might need to
 986          * access HPET !
 987          */
 988         lapic_timer_state_broadcast(pr, cx, 1);
 989
 990         kt1 = ktime_get_real();
 991         /*
 992          * disable bus master
 993          * bm_check implies we need ARB_DIS
 994          * !bm_check implies we need cache flush
 995          * bm_control implies whether we can do ARB_DIS
 996          *
 997          * That leaves a case where bm_check is set and bm_control is
 998          * not set. In that case we cannot do much, we enter C3
 999          * without doing anything.
1000          */
1001         if (pr->flags.bm_check && pr->flags.bm_control) {
1002                 spin_lock(&c3_lock);
1003                 c3_cpu_count++;
1004                 /* Disable bus master arbitration when all CPUs are in C3 */
1005                 if (c3_cpu_count == num_online_cpus())
1006                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
1007                 spin_unlock(&c3_lock);
1008         } else if (!pr->flags.bm_check) {
1009                 ACPI_FLUSH_CPU_CACHE();
1010         }
1011
1012         acpi_idle_do_entry(cx);
1013
1014         /* Re-enable bus master arbitration */
1015         if (pr->flags.bm_check && pr->flags.bm_control) {
1016                 spin_lock(&c3_lock);
1017                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
1018                 c3_cpu_count--;
1019                 spin_unlock(&c3_lock);
1020         }
1021         kt2 = ktime_get_real();
1022         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
1023
1024         sleep_ticks = us_to_pm_timer_ticks(idle_time);
1025         /* Tell the scheduler how much we idled: */
1026         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
1027
1028         local_irq_enable();
1029         current_thread_info()->status |= TS_POLLING;
1030
1031         cx->usage++;
1032
1033         lapic_timer_state_broadcast(pr, cx, 0);
1034         cx->time += sleep_ticks;
1035         return idle_time;
1036 }
1037
1038 struct cpuidle_driver acpi_idle_driver = {
1039         .name =         "acpi_idle",
1040         .owner =        THIS_MODULE,
1041 };
1042
1043 /**
1044  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1045  * @pr: the ACPI processor
1046  */
1047 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1048 {
1049         int i, count = CPUIDLE_DRIVER_STATE_START;
1050         struct acpi_processor_cx *cx;
1051         struct cpuidle_state *state;
1052         struct cpuidle_device *dev = &pr->power.dev;
1053
1054         if (!pr->flags.power_setup_done)
1055                 return -EINVAL;
1056
1057         if (pr->flags.power == 0) {
1058                 return -EINVAL;
1059         }
1060
1061         dev->cpu = pr->id;
1062         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1063                 dev->states[i].name[0] = '\0';
1064                 dev->states[i].desc[0] = '\0';
1065         }
1066
1067         if (max_cstate == 0)
1068                 max_cstate = 1;
1069
1070         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1071                 cx = &pr->power.states[i];
1072                 state = &dev->states[count];
1073
1074                 if (!cx->valid)
1075                         continue;
1076
1077 #ifdef CONFIG_HOTPLUG_CPU
1078                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1079                     !pr->flags.has_cst &&
1080                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1081                         continue;
1082 #endif
1083                 cpuidle_set_statedata(state, cx);
1084
1085                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1086                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1087                 state->exit_latency = cx->latency;
1088                 state->target_residency = cx->latency * latency_factor;
1089                 state->power_usage = cx->power;
1090
1091                 state->flags = 0;
1092                 switch (cx->type) {
1093                         case ACPI_STATE_C1:
1094                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1095                         if (cx->entry_method == ACPI_CSTATE_FFH)
1096                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1097
1098                         state->enter = acpi_idle_enter_c1;
1099                         dev->safe_state = state;
1100                         break;
1101
1102                         case ACPI_STATE_C2:
1103                         state->flags |= CPUIDLE_FLAG_BALANCED;
1104                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1105                         state->enter = acpi_idle_enter_simple;
1106                         dev->safe_state = state;
1107                         break;
1108
1109                         case ACPI_STATE_C3:
1110                         state->flags |= CPUIDLE_FLAG_DEEP;
1111                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1112                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1113                         state->enter = pr->flags.bm_check ?
1114                                         acpi_idle_enter_bm :
1115                                         acpi_idle_enter_simple;
1116                         break;
1117                 }
1118
1119                 count++;
1120                 if (count == CPUIDLE_STATE_MAX)
1121                         break;
1122         }
1123
1124         dev->state_count = count;
1125
1126         if (!count)
1127                 return -EINVAL;
1128
1129         return 0;
1130 }
1131
1132 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1133 {
1134         int ret = 0;
1135
1136         if (boot_option_idle_override)
1137                 return 0;
1138
1139         if (!pr)
1140                 return -EINVAL;
1141
1142         if (nocst) {
1143                 return -ENODEV;
1144         }
1145
1146         if (!pr->flags.power_setup_done)
1147                 return -ENODEV;
1148
1149         cpuidle_pause_and_lock();
1150         cpuidle_disable_device(&pr->power.dev);
1151         acpi_processor_get_power_info(pr);
1152         if (pr->flags.power) {
1153                 acpi_processor_setup_cpuidle(pr);
1154                 ret = cpuidle_enable_device(&pr->power.dev);
1155         }
1156         cpuidle_resume_and_unlock();
1157
1158         return ret;
1159 }
1160
1161 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1162                               struct acpi_device *device)
1163 {
1164         acpi_status status = 0;
1165         static int first_run;
1166 #ifdef CONFIG_ACPI_PROCFS
1167         struct proc_dir_entry *entry = NULL;
1168 #endif
1169         unsigned int i;
1170
1171         if (boot_option_idle_override)
1172                 return 0;
1173
1174         if (!first_run) {
1175                 if (idle_halt) {
1176                         /*
1177                          * When the boot option of "idle=halt" is added, halt
1178                          * is used for CPU IDLE.
1179                          * In such case C2/C3 is meaningless. So the max_cstate
1180                          * is set to one.
1181                          */
1182                         max_cstate = 1;
1183                 }
1184                 dmi_check_system(processor_power_dmi_table);
1185                 max_cstate = acpi_processor_cstate_check(max_cstate);
1186                 if (max_cstate < ACPI_C_STATES_MAX)
1187                         printk(KERN_NOTICE
1188                                "ACPI: processor limited to max C-state %d\n",
1189                                max_cstate);
1190                 first_run++;
1191         }
1192
1193         if (!pr)
1194                 return -EINVAL;
1195
1196         if (acpi_gbl_FADT.cst_control && !nocst) {
1197                 status =
1198                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1199                 if (ACPI_FAILURE(status)) {
1200                         ACPI_EXCEPTION((AE_INFO, status,
1201                                         "Notifying BIOS of _CST ability failed"));
1202                 }
1203         }
1204
1205         acpi_processor_get_power_info(pr);
1206         pr->flags.power_setup_done = 1;
1207
1208         /*
1209          * Install the idle handler if processor power management is supported.
1210          * Note that we use previously set idle handler will be used on
1211          * platforms that only support C1.
1212          */
1213         if (pr->flags.power) {
1214                 acpi_processor_setup_cpuidle(pr);
1215                 if (cpuidle_register_device(&pr->power.dev))
1216                         return -EIO;
1217
1218                 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1219                 for (i = 1; i <= pr->power.count; i++)
1220                         if (pr->power.states[i].valid)
1221                                 printk(" C%d[C%d]", i,
1222                                        pr->power.states[i].type);
1223                 printk(")\n");
1224         }
1225 #ifdef CONFIG_ACPI_PROCFS
1226         /* 'power' [R] */
1227         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1228                                  S_IRUGO, acpi_device_dir(device),
1229                                  &acpi_processor_power_fops,
1230                                  acpi_driver_data(device));
1231         if (!entry)
1232                 return -EIO;
1233 #endif
1234         return 0;
1235 }
1236
1237 int acpi_processor_power_exit(struct acpi_processor *pr,
1238                               struct acpi_device *device)
1239 {
1240         if (boot_option_idle_override)
1241                 return 0;
1242
1243         cpuidle_unregister_device(&pr->power.dev);
1244         pr->flags.power_setup_done = 0;
1245
1246 #ifdef CONFIG_ACPI_PROCFS
1247         if (acpi_device_dir(device))
1248                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1249                                   acpi_device_dir(device));
1250 #endif
1251
1252         return 0;
1253 }